This invention relates to energy absorbing bumpers and energy absorbing bumper modules which are primarily intended to be located on vehicles to protect them from the effects of the impact forces imparted during collision with other objects.
Many efforts have been made to reduce the damage done as a result of the collision of a vehicle with another vehicle or with a fixed object. One type of device which has attained technical and commercial success is of the type described in U.S. Pat. No. 3,284,112 issued to J. W. Rich. That device is based upon the absorption of the collision forces by a liquid.
Other collision bumpers have been developed using cellular materials or resilient rubber like substances. One of the problems with these collision bumpers is that they tend to react very much like a linear spring and store the energy imparted during a collision rather than absorbing or dissipating it. This stored energy is then almost immediately returned to the impacting body in the form of a severe rebound which has a number of unacceptable side effects. In particular, the rebounding effect can result in whiplash and the possibility of resultant neck, back and spinal injuries to the passengers in the vehicles.